brechtm/citeproc-py — pull request #19 by davidlesieur (2014-11-11 23:50:20+00:00)
Title: Avoid crash when there is nothing to affix.

Method Affixed.wrap() can be passed a None argument (e.g. from Layout.render_bibliography(), when render_children() returns None).

This change adds some validation to prevent it from crashing in that case.